It's an idiom.
raining buckets/cats and dogs
No! 'its raining cats and dogs' is an Idiom.
"It's raining cats and dogs" is an idiom.
The phrase "it's raining cats and dogs!" is hyperbole.
Raining cats and dogs mean that it's raining very hard
There is an expression - "raining cats and dogs". This does not mean that cats and/or dogs are literally falling from the sky, it simply means that it is raining very hard.
under what headword would you find the idiom raining cats and dogs?
Its raining cats and dogs!
It is raining heavily
In olden times people threw rubbish into the street. In amongst the rubbish would be cats and dogs which would be washed along the street during heavy rain. Hence raining cats and dogs. Of course, they are not literally raining from above!
Its raining cats and dogs
Beacuse someone told him it was raining cats and dogs